Germicidal nonionic-detergent iodine compositions



Patented Nov. 28, 1957 3,355,386 GERMICIDAL NONIONIC-DETERGENT IODINECOMPOSITIONS Abraham Cantor, Elkins Park, Pa., and Murray W.

Winicov, Flushing, N.Y., assignors to West Laboratories, Inc., LongIsland City, N.Y., a corporation of New York No Drawing. Filed Oct. 19,1965, Ser. No. 498,130 Claims. (Cl. 252-106) This invention relates tononionic detergent-iodine complexes which provide enhanced iodine colorin use dilutons, and to germicidal compositions contaning suchcomplexes. More particularly, the invention relates to suchdetergent-iodine complexes wherein a substantial color enhancement isprovided by detergent components which are water-soluble condensates ofethylene oxide and a hydroxy compound providing a hydrophobic moietyhaving an average aliphatic carbon content in the C to C range, andwherein further color enhancement is provided by detergent componentshaving the hydrophobic moiety characterized as above described, buthaving the ethylene oxide partially replaced or supplemented bypropylene oxide.

It has been known for many years that detergent complexed iodinesolutions show increased color over aqueous iodine solutions. Thedifferences among detergent classes with respect to iodine color havenot been taught, although some of those skilled in the art, may be awareof such dilferences. The difl erences in detergent-iodine color within aparticular class of detergents is not known, and has never beendescribed before.

Most iodine use dilutions for cleaning purposes are made at the 25p.p.m. to 75 ppm. available iodine level. At these levels the iodinecolor can readily be seen; differences in color as a function of thedetergent, measurable by instrument, can hardly be detected by eye andso have never attracted attention. Dilutions at the 12% ppm. level, usedexclusively as a sanitizing rinse, have beenonly faintly colored. Sincesuch solutions are used on surfaces that are clean to begin with, thereis almost no loss of iodine through reaction with proteinaceous soil,and so the problem of viewing the color as a measure of whenreplenishment is necessary is not of great importance. To the extentthat improved color of detergent-iodine use dilutions can extend therange of iodine perception, the amount of iodine necessary in usedilutions for both the cleaning and sanitizing purposes can be safelylowered. This is for the reason that iodine is recognized asgermicidally active in concentrations as low as fractions of a p.p.m.

It has been suggested in Shelanski Patent No. 2,931,- 777 that as thedetergent component of germicidal detergent iodine composition there maybe employed polyalkylene oxide derivatives of water-insoluble aliphatichydroxy compounds. It has been found that such detergents vary widely iniodine complexing capacity and in properties of the resultingdetergent-iodine compositions with variations in both the hydrophobicand the hydrophilic components. Such variation is in no way suggested bythe disclosure of said patent, and in fact, the patent contains nospecific disclosure or illustrative examples of compositions in whichiodine is complexed with condensates of water-insoluble aliphatichydroxy compounds and ethylene oxide.

It has been discovered, in accordance with the present invention, thatprimary aliphatic alcohols having an average carbon content within the Cto C range, and preferably within the C to C range will, when condensedwith ethylene oxide, provide detergents which can be employed as iodinecarriers with superior effectiveness. Detergents formed from secondaryalcohols are distinctly inferior as iodine carriers.

It is therefore an underlying concept of the present invention that thenew detergent-iodine compositions contain a detergent in which thehydrophobic moiety is a primary aliphatic alcohol, or primary aliphaticalcohol mixture of the C to C and preferably the C to C range. In thisconnection, it is to be understood that such alcohols and the detergentsformed therefrom are generally not individual compounds, but mixturescharacterized by average carbon atom content. Thus, a commercial Calcohol may itself be a mixture of two, three or more alcoholscontaining as few as 10 or as many as 20 or more carbon atoms inproportions to average C for the mixture.

Until recently commercial primary aliphatic alcohols were derived fromnatural products containing even numbered fatty acids. Today there aresynthetic primary alcohols available which may contain mixtures of oddand even numbered carbon chains, or which may be exclusively evennumbered. It has been found that there is no significant differencebetween even and odd numbered primary aliphatic alcohols as componentsof detergents used in the present invention.

Where ethylene oxide is condensed with the C to C and preferably C to Calcohols, the products vary from water insoluble liquids, toWater-soluble Waxes and solids as the amount of condensed ethylene oxideis increased. Water solubility, and hence suitability for use as iodinecarrier, is generally reached when the number of carbon atoms suppliedby the ethylene oxide approximately equals or exceeds the number ofcarbon atoms in the alcohol. Expressed another way, the number of molesof ethylene oxide should be at least with n being the average number ofcarbon atoms in the alcohol component. Thus, a C alcohol condensed with5 or more moles of ethylene oxide and a C alcohol condensed with 7 ormore moles of ethylene oxide will generally'be water-soluble andsuitable for use as an iodine carrier.

In many detergent-iodine preparations, it is preferable that thedetergent-iodine complex itself be a liquid, although in specialinstances, as where a dry, powdered composition is desired, it can be awaxy or solid complex. Furthermore, it is possible, although somewhatmore difficult, to prepare aqueous liquid concentrates when using waxyor solid detergents. There is therefore, no well defined upper limit tothe amount of ethylene oxide which should be condensed with the alcohol.It should be noted,

however, that when liquid complexes are desired, the proportion ofethylene oxide to alcohol becomes quite limited, and progressively morelimited as the alcohol contains more carbon atoms. Thus, with a Calcohol, the presence of 20 or more moles of ethylene oxide willgenerally provide a Waxy condensate, whereas with a C and C alcohol, allwater-soluble ethylene oxide condensates are of'waxy or solid form. Itshould be noted that ethoxylated mixed primary alcohols may containsubstantial amounts of the higher molecular Weight alcohols and stillprovide a water-soluble, liquid condensate; and such mixtures arepreferable in most instances to ethoxylated single alcohols.

Just as there is a minimum of E0, about solubility, there is a pointbeyond which the further addition of EO only serves to dilute thechromophoric entity.

In general, this less desirable point is reached when about Zn-l molesof E have been added. Primary aliphatic alcohols containing 2n1 moles ofE0, do not give satisfactory detergent-iodine solution colors at the 6p.p.m. iodine level unless considerable excesses of detergent are used.I

The water-soluble alcohol-ethylene oxide condensates, whether in theform of liquids or waxy solids, can be complexed with iodine by merelymixing together the detergent and elemental iodine at suitably elevatedtemperatures, i.e., about 50 C. or such higher temperature as isnecessary to melt the waxy detergent. When the detergent is a liquid,the complexing can even be effected by room temperature mixing, but theextended time required makes this impractical.

A preferred method of preparing the complexes is the coldmixing processdisclosed in United States Patent No. 3,028,299, wherein iodine issupplied as an aqueous iodide-iodine solution suitably containing about57% by weight I 20% HI and the balance water. This method isparticularly desirable in preparing iodine complexes with waxy or solidalcohol-ethylene oxide condensates.

The detergent-iodine complexes of the present invention. may be employedin germicidal compositions containing amounts of detergent within therange of about 0.5 to'75%, and of available iodine within the range ofabout 0.1 to 25%. Compositions containing about 115% available-iodineand 575% detergent are suitable for products which can be diluted withwater when used by a consumer. Compositions containing from about 15-25% available iodine and about 60-75% detergent can be used asmanufacturing concentrates. Compositions in which the available iodineis from about 0.1 to 1.0% containing about 0.5 to detergent may besuitably used directly without dilution with water. In non-acidifiedproducts for general environmental sanitation purposes, the remainder ofthe composition can be water, or a mixture of water andisopropyl-alcohol. On the other hand, for dairy use and other usesencountering excessive amounts of organic soil, it is preferable toemploy as added components, a mixture of water with compatible acids.

When compositions are prepared by the cold method using the abovementioned aqueous HI-iodine solution, the composition will also containabout 1 part of I" to each 3 parts of I Thus, a composition containing1.5% Is will contain about 0.5% I.

. An important advantage of the new compositions is the superiorbuilt-in indicator provided in typical use dilutions of 25 p.p.m., 12.5p.p.m., and particularly 6 p.p.m. due to the enhanced color of suchsolutions. It is the practice to instruct customers usingdetergent-iodine compositions to discard use dilutions when thecharacteristic iodine color is gone. With many available compositions,however, the color at dilutions as low as 10 to p.p.m., becomes so faintthat end point detection becomes difiicult. Such use dilutions arefrequently discarded when as much as 50 to 75% of their germicidalactivity remains unconsumed. The well established public health utilityof decimal p.p.m. concentrations of available iodine further underscoresthe significance of lowering the threshold of visibility of iodinecolor. Any sharpening of the end point by providing greater colorintensity at the lower use dilutions is also of substantial economicimportance in enabling the customer to realize greater sanitizing valuefrom a given amount of detergent-iodine composition.

The enhanced colorat use dilutions as low as the 5 to 10 ppm. range hasbeen found to be primarily a function of the number of carbon atoms inthe primary alcohol which is condensed with ethylene oxide. Best resultsare obtained with condensates in which the alcohol component has anaverage of 14 to 18 carbon atoms; and there is a sharp drop-off of colorintensity when switching 4 from condensates derived from C to C primaryalcohols.

Secondary alcohols form condensates with ethylene oxide which willcomplex with iodine, but there is excessive reaction between the iodineand the condensate, with resulting drop in available iodine, which makessuch condensates unsatisfactory. In fact, such interreaction 15 sopronounced when combining with iodine by the normal hot process, that asshown below, a charting results which completely masks the iodine colorat low use dilutions, thereby negating this most unique property ofgermicidal iodine solutions. It is significant that mostdetergent-iodine manufacturers at this time use the hot process. Theinherent instability of secondary alcoholiodine combinations is such asto make their use questionable even in compositions made under milderconditions where the decomposition takes longer to become evident.

The color enhancing effectof condensates of C to C primary alcohol withethylene oxide does not appear to be greatly modified by moderatevariation in the ethylene oxide content. As previously indicated,thenumber of carbon atoms provided by the ethylene oxide should be aboutequal to, or greater than, the number of carbon atoms in the alcohol.The preferred range appears to be about 1 to 2.5 ethylene oxide carbonsper primary alcohol carbon. On the other hand, as will be more fullyhereinafter described, there is a substantial color enhancement whenpart of the ethylene oxide is replaced with, or supplemented by,propylene oxide.

Increase in the proportion of detergent to iodine provides a distinctenhancement of color intensity at low use dilutions. In moving from a 5to 1 to 10 to l detergent to iodine ratio, the color intensity isgenerally about doubled. This is of special significance in view of thefact that, for compositions with recommended sanitation uses below the25 p.p.m. iodine level, it is desirable to use progressively higherratios of detergent to iodine, in order to provide an effective amountof detergent in the more dilute use solutions.

As a means for reliably recording and comparing color indetergent-iodine solutions, it is practical to use an l strument such asa Beckman spectrophotometer. Color is measured in terms of absorbance, adecimal value obtained as log micelle concentration (cmc) of nom'onicdetergents. S. Ross and J. P. Qlivier, in a paper entitled A Method forthe Determination of Critical Micelle Concentrations of,

Un-ionized Association Colloids in Aqueous or in NonaqueousSolutions (J.Phys. Chem. 63 1671 (1959)) de-. scribe how solutions of elementaliodine can be used to determine the cmc in much the same way as withdyes, which are frequently used for crnc determinations, The

iodine is superior to dyes in general owing to the small molecular sizeof iodine compared to dyes; the iodine thereby does not interfereappreciably with the detergent agglomerate. A 25 p.p.m. aqueous solutionof elemental iodine was used by Ross, to which were added varyingamounts of a stock detergent solution. The light absorp-, tion at 360 mgwas measured and was plotted as a fling? tion of detergentconcentration. The inflection point in' this graph was taken as the crncyalue. The maximum light absorption in Ross experiments was always foundat 360 mu. I

There is no relationship between the novel subject matter of thisapplication and any of the subject matter in the above reference for thefollowing reasons. It has been found that detergent-iodine solutionscharacteristic of the environmental sanitation art, exhibit absorptionpeaks considerably closer to the visible region. That is, as shownbelow, the peak values are at 385-398 m rather than at 360 mp. This isan important difference in that any visual utility of such resultsdepends on the magnitude of the portion of the curve which is beyond 400m in the visible region. The peak value is a good representation of, andis proportional to, the values beyond 400 me. It is customary to readabsorption at the peak value, since this gives the highest degree ofaccuracy.

Ross results give absolutely no insight into the relationship betweencolor and chemical constitution within the members of a homologousseries. One might therefore incorrectly predict from Ross results thatthe addition of further ethylene oxide to a water-soluble molecule,which increases the cmc, would result in a detergent which would showless color with iodine, since an equivalent concentration would bring itcloser to its inflection point. This is certainly not the general casewhen detergents having the same starting alcohol are compared. Table Ashows that the results for the pairs No. 2 and No. 4 and No. 14 and No.15 gives the opposite effect. The series No. 11, No. 12, and No. 13which shows a small decrease because the results are given on a weightpercent basis, actually reverse when the detergent concentrations argiven on a molecular weight basis.

For the purpose of evaluating detergent-iodine compositions of thepresent invention, however, it is essential that elemental or availableiodine be distinguished from iodide which may be formed in, or added to,the composition. It has been found, for example, that while addition ofiodide to a detergent-iodine solution provides some enhancement ofcolor, it is of small magnitude compared to the color change withvariations of available iodine concentration. Since iodide alone withdetergent produces no color, the color enhancement above mentionedindicates intensifying of color of the detergent-iodine complex in thepresence of iodide.

An effective measure of the iodine complexing in the newdetergent-iodine compositions is the distribution coefiicient (D.C.)determined in a two-phase aqueous-heptane system according to theprocedure disclosed in the above mentioned United States Patent No.3,028,229. Surprisingly, a number of the new compositions in whichiodine is complexed with a C to C primary alcoholethylene oxidecondensate, show substantially higher D.C. values than similarcompositions containing the conventional nonyl-phenol-ethylene oxidecondensate.

A final standard to be considered in evaluating the new compositions iscloud point. This is the temperature above which detergents anddetergent-iodine complexes in aqueous solution change from clear ortransparent solutions to cloudy solutions or suspensions. In general,the cloud point of liquid germicidal products or concentrates should beat least 50 C., and preferably above about 55 C. in order that suchproducts will remain clear and transparent under all normal storageconditions.

The unique color enhancing properties as above described for the C to Cprimary alcohol-ethylene oxide condensates complexed with iodine arealso found to be present to a substantial extent in detergent-iodinecomplexes in which the detergent is a condensate of ethylene oxide withan alkyl phenol in which the alkyl substituent comprises one or moreprimary aliphatic radicals having a total of 12 to 18 carbon atoms.Typical examples of such detergents are condensates of ethylene oxidewith dodecylphenol, dioctylphenol, and dinonylphenol in which the amountof ethylene oxide is at' least sufficient to impart water solubility tothe detergent. Suitably, the number of moles of ethylene oxide can be inthe range of about .8 to 3 times the number of carbon atoms in the alkylsubstituent.

Under comparable conditions, these higher alkyl-phehol-ethylene oxidecondensates provide iodine complexes having more than twice the colorintensity at 6 p.p.m. available iodine dilutions than complexes formedwith the conventional nonylphenol-ethylene oxide condensates.

Another embodiment of the present invention resides in the discoverythat still further color enhancement can be achieved with the primaryalcohol type detergents if at least part of the condensed ethylene oxideis replaced with, or supplemented by, ropylene oxide. Such modifieddetergents can be represented by the following formula:

wherein R is C to C primary alkyl, the weight percent of E0 is withinthe range of 0 to 45% in one of the blocks, x, y and within the range 60to 100% in the other of the blocks x, y, and the total number of molesof alkoxide is in the range of 6 to 40 moles, with l to 10 moles in thePO rich block, and 5 to 30 moles in the E0 rich block.

Generally preferred among the detergents above described are those inwhich the block x contains 0 to E0, and provides 1 to 4 moles ofalkoxide, while the block y contains 60 to 90% E0, and provides 5 to 20moles of alkoxide.

Preferred detergents of this modified type provide iodine complexeshaving under comparable conditions, a color intensity at 6 p.p.m.dilution which is more than four times as great as the conventionalnonyl-phenol ethylene oxide-iodine complex. Furthermore, the modifieddetergents can be in liquid form even when the average number of carbonatoms in the radical R is as high as C Both of these factors are ofdistinct advantage in the formulation and useof germicidaldetergent-iodine compositions.

The following examples show the preparation of typical detergent-iodinecompositions suited for varied environmental sanitation uses andemploying the color enhancing detergent-iodine complexes of the presentinvention. It is to be understood however, that these examples are givenby way of illustration and not of limitation.

Example I A number of detergent iodine compositions were prepared usingvarious primary alcohol-ethylene oxide condensates as detergents. Thesecompositions are all aqueous solutions containing 10% detergent, 1%available iodine, and 0.35% iodide (1*) by weight, the iodine and iodidebeing supplied as HI-Iodine solution containing 57% available iodine and20% HI.

In Table A, detergents are identified by the number of carbon atoms inthe primary alcohol component, the number of moles of condensed ethyleneoxide, the cloud point of a 1% aqueous solution, and the physical stateat 25 C. For the resulting detergent-iodine compositions, values aregiven for distribution coefiicient (D.C.) as determined by the formula:

ml. heptane ml. aqueous phase mg. I in aqueous phase D.C.=

mg. I in heptane log for unit path length, where I and I are the lightin and light out respectively. A Beckman Du spectrophotometer with cellsof 1.00 cm. path length were used.

TABLE A V Cloud Relative Color (Absorbance) Sample No. Atoms of CarbonMols Point, Phys. State 25 p.p.m. ETO 0. at 25 C. Peak (m D.C 25 ppm12.5 p.p.m. 6 p.p.ni

11 av 10-1- 5.9 27 Liquid .245 .045 .010 300 Nonylpheno 10. 5 75 500 100025 885 PIUIOIliO P65 80 .150 .044 .009 860 In Control A sample, thedetergent is a nonyl phenol 20 ethylene oxide condensate widely used indetergent-iodine TABLE B compositions. Control B, another nonionicdetergent extensively used in detergent-iodine compositions is a con- SI Absorbanee at my densate of polyoxypropylene having a molecular weightamp e 7 a 4 V of 17 5,0 with ethylene oxide in an amount to provide 50%350 3.60 370 380 385 890 400 2 450. by weight in said condensate. Allsamples, with the excep- 7 A H011 0f and 2 Show much bettel o at all(111111098, 9 760 895 .550 32.5 and particularly at the 6 p.p.m.dilution where any 111- 15 .510 .595 .700 .805 .820 .820 .790 .545 .330crease of color is of very real significance.

Sample I is included for comparison purposes to show the poor colorobtained when the starting alcohol is below the C -C range. The color ismost deficient at the levels of 6 and 12.5 p.p.m. available iodine.

Sample 2, approximately equal to the Control A, represents a combinationof minimum length carbon chain in the alcohol moiety and minimalethylene oxide.

- The preferred samples in Table A are considered to be 8, 9 and 15. Thedetergents in both 8 and 9 are liquids, which as previously indicated,are preferable to solids, and

Example 11 Relative Color as a Function of Detergent Concentration thedetergent of 8 is somewhat more readily available than that of 9. As forsample 15, the disadvantage of the solid form of the detergent is offsetby the unusually high color value at the 6 p.p.m. dilution.

'With respect to the three preferred samples, there is shown in thefollowing tabulation, the variation of absorbance at difierent wavelengths (111,41) for the 25 p.p.m. dilution.

The foregoing comparisons indicate that increasing the proportion ofdetergent causes an increase in the color intensity at all dilutions,with the effect being greatest at the p-p-miodin qe t i n, h r nh ncemeno c or is of greatest importance. The data further indicates that thecolor. improvement increases most rapidly when the proportion ofdetergent to available iodine increases iron;

9 Example III In order to demonstrate the eifect of variation in theproportion of iodide, compositions similar to the preferred samples 8and 9 of Example I (and here identified as 8b and 9b) were preparedhaving iodide proportions equal to and approximately four times as greatas in Example I, and these compositions at varying dilutions were testedfor absorbance with the following results:

10 grams of a C primary alcohol-ethylene oxide condensate containing 8.1moles of ethylene oxide (detergent No. 8 in Example I) forming a clear,dark mahogany colored liquid having a specific gravity at 60 F. of 1.276and a viscosity at C. of 280 c.p.s. Immediately after preparation, theavailable iodine was 20.4%, and after accelerated ageing by storing fortwo weeks at 125 F., the available iodine was found to be 20.2%(indicating very good stability).

Relative Color as a Function of Iodine Concentration 250 p.p.m.Detergent 125 p.p.m. Detergent 63 P.P.m. Deterg n p.p.m. I; 12.5 ppm. 1;6 ppm. 1:

9 ppm. I- 34 p.p.1n. I- 4.5 p.p.m. I- 17 ppm. I" 2 p.p.1n I" 8 p.p.m. I-

8b .80 (390 m 92 (380 m 240 330 060 085 9b 90 (385 1111.1) 1. 06 (380mu) 310 395 090 125 The foregoing comparisons indicate that smallvariations in iodide content do not have too great an effect on color.The color enhancement which characterizes the primary alcohol-ethyleneoxide detergents as iodine complexing agents can be realized whenformulating by both the standard hot mix method and by the cold processusing aqueous iodine-iodide solution.

Example IV A commercial high acid detergent iodine composition used fordairy and similar cleaning operations, and having a guaranteed availableiodine content of 1.75%, contains by weight 19% detergent (a mixture of15.7 parts nonyl phenol ethylene oxide condensate containing 10.5 molesof ethylene oxide per mole of nonyl phenol and 3.3 parts ofpolyoxypropylene condensed with ethylene oxide providing a molecularweight of 1750 in the polyoxypropylene component and 20% of condensedethylene oxide), 3.3% of HI-iodine (supplied as an aqueous solutioncontaining 57% available iodine and 20% HI) 21.25% of H 'PO (commercial75% acid) and Water to 100%.

With this product as a control, similar products were preparedsubstituting as detergent 19% of certain of the primary alcohol ethyleneoxide condensates of Example I. For ease of cross-reference, thesedetergents are here identified by the same sample number followed by thesubscript c."

These samples and the control are compared in terms of cloud point anddistribution coefficient (DC) of the product and the absorbance of 1 to640 (12.5 p.p.m. I use dilutions thereof, with the results shown in thefollowing table:

The tested samples show generally better cloud points and distributioncoefiicients than the control, and of particular significance is themarkedly higher absorbance at the practical 12.5 ppm. I use dilution.

Example V A germicidal detergent-iodine concentrate is prepared bymixing together at room temperature 360 grams of an HI-I solution asdescribed in Example I and 640 This concentrate is suitable for sale anddistribution to formulators who will add water, acid, additionaldetergent, or combinations of these in preparing consumer products. 7

Examples I to V show the advantages of primary alcohol ethylene oxidecondensates as detergent components of detergent-iodine compositoins.The following three examples are included to demonstrate theunsatisfactory nature of secondary alcohol-ethylene oxide condensates.

Example VI Two of the detergent-iodine compositions of Example 1V,samples and 9c are compared with similar detergent-iodine compositionscontaining as detergent component Secondary A-a secondary alcoholcontaining 11 to 15 (average 13) carbon atoms condensed with 9 moles ofethylene oxideand Secondary Ba secondary alcohol containing 11 to 15(average 13) carbon atoms condensed with 13 moles of ethylene oxide.

The samples were tested for initial available iodine content, thensubjected to industry standardized accelerated storage conditions bymaintaining at 125 F. for two weeks and again tested for availableiodine, with the following results:

Stored two weeks Sample Initial It, percent at 125 F.

I1, percent 1. 93 1. 82 1. 1. 89 Secondary A 1. 93 1. 67 Secondary B 1.92 1. 66

Since as noted in Example IV this type product should have a guaranteediodine content of 1.75%, it is apparent that the secondary A and Bsamples are unsatisfactory, whereas the Sc and 90 samples show verylittle iodine loss in the accelerated ageing test. The two weeks at 125F. is generally comparable to a full year under normal storageconditions.

Example VII A typical detergent-iodine composition without phos phoricacid, intended for general environmental sanitation purposes, and havinga guaranteed available iodine content of 1.6% contains 15% detergent,3.3% HI-iodine (supplied as an aqueous solution containing 57% availableiodine and 20% HI), 2% of isopropyl alcohol, and water to This typecomposition was made up using the two preferred detergents from ExampleI, here identified as 8d and 9d, and the two detergents derived fromsecondary alcohols, Secondary A and Secondary B as described in ExampleV, and were tested for available iodine before 1 1 and after thestandard two weeks, storage at 125 F., with the following results:

Stored two weeks Sample initial 1 percent at 125 F.

I2, percent 1.91 1. 71 1. 91 1. 77 Secondary A- 1. 93 1. 56 Secondary B1.92 1. 5.6

Here again the compositions using ethoxylated secondary alcohols as thedetergent component fall below the guaranteed iodine content in thestandard accelerated ageing test. Furthermore, comparing Examples V andVI serves to indicate that the presence of the phosphoric acid was not afactor, but that the poor results with the ethoxylated secondaryalcohols must be due to a chemical instability, i.e. a reactivitybetween the secondary al-. cohol moiety and the iodine. This is furtherconfirmed y the fo lo n xamp Example VIII Following the conventionalformulating procedure of Example IX Following the procedure of Example Ian aqueous detergent-iodine solution containing by weight 10% detergent,1% available iodine and 0.35% iodide (I') using as detergentdodecylphenol condensed with 12 moles of ethylene oxide. This detergentis a liquid at C, and in 1% aqueous solution has a cloud point of 60.The detergent-iodine solution has a distribution coe f cie f d w e e tedr rel i e color or bsorbance as in Example I, gave results shown in thefollowing tabulation, and compared with the values for Control A fromExample 1:

Relative Color (nbsorbance) 25 ppm. Detergent peak (my) 25 p.p.m. 12.5ppm. 6 p.p. m.

Dodecylphenol 12 moles EtO 710 215 055 385 Nonylphenol 10.5 moles EtO660 160 025 385 cooking detergent and elemental iodine for about 4 hoursat 55 to 60 C., comparative formulations were prepared using 72 parts ofdetergent and 28 parts of elemental iodine, the cooking being effectedin a three necked flask equipped with Teflon stirrer, thermometer andpressure equalization port. Following the heating period, the batch wascooled, analyzed for available iodine, and the residual color afterneutralizing the iodine with thiosulfate as notedhe sampl ma k rimary mpoyed e. pr f r e ethoxyla ed pr ma y alcoh (samp 8 o Ex mp e d e samplemark d Secondary u d the cth xy ated secondary alcohol described asSecondary A in Ex ample The comparative results are as follows:

This enhancement of color in dilute solutions is characteristic ofdetergent-iodine compelexes containing as detergent componentalkylphenol-ethylene oxide condensates in which primary alkylsubstituents provide 12 to 18 car bon atoms, with the color enhancementgenerally increase ing as the number of carbon atoms is increased.

Example X RO(EO,PQ)x(EO,PO) I-I Eran A V311 6 .2 e igo Wt. ercent E0 inmMol s E0. .320 Sample T2361)" Final Detergent Color Detergent Carbon p em in Th Kn. My" ry" Primeval- Q 25. O 57 Colorless. 14 25 Secondary...23.0 22.0 57 vetdark Caramel. 14 75 .25 13.7 15 25 75. 4.3 1416 12 25 753.4 11.7 14 15 as 3.9 14.0 Both the high iodine loss and the charredcolor of the E 43 52, {8'3 detergent confirm the suspected reactivity ofiodine with 33 67 12-;

the secondary alcohol type detergent. It will be noted in The detergentsand the aqueous solutions of their iodine complexes were tested as inExample I, and the results are tabulated below together with the valuesfor preferred hol moiety with an average carbon content within the rangeof C to C and samples 8, 9 and 15 from Example I: 1

Detergent Aqueous Complex 25 p.p.m. Sample Cloud Physical Relative Color(absorbance) peak Pt., State, (my) C. 25 C.

D.O. 25 p.p.m. 12.5 p.p.m. 6 p.p.m.

It is significant to note that Sample provides distinctly better colorat the three dilutions than the comparative samples from Table I andthat the color value at each dilution is at least 10% better than thevalues for sample I-9, which is the best performing liquid detergent inExample I. The color values for sample d in which R represents C aresubstantially higher than the comparable color values for samples 2, 3,4 and 5 in Table A of Example I. There is therefore a clear indicationfrom the color values for samples a to it above that the basic increasein color when increasing the alkyl carbon content above C is amplifiedby the substitution of the mixed EO,PO for the ethylene oxide of ExampleI as the alkoxide component of the detergent.

In summary, it is to be noted that while three apparently quitedifferent type detergents have been describd in the foregoing examples,they share the common and highly practical characteristic of providingenhancement in iodine color at all conventional use dilutions and atdilutions heretofore considered impractical due to the faintness orabsence of iodine color. Expressed in another way, the newdetergent-iodine complexes coming within the present invention are thosecharacterized as providing enhanced iodine color as evidenced by anabsorbance,

I 0 log I 1 cm., of greater than .035, and preferably at least .045 whenmeasured at the 6 ppm. available iodine level with a 10:1 ratio ofdetergent to iodine. Complexes of the three types described whichmeasure up to this characteristic, and have a detergent to availableiodine ratio of at least 3:1, and detergent-iodine compositionscontaining such complexes are considered as falling within the presentinvention, no matter whether such compositions are in the form ofcommercial concentrates, consumer products intended for dilution, or enduse products adapted for use without dilution.

Various changes and modifications in the detergentiodine compositionsherein disclosed will occur to those skilled in the art, and to theextent that such changes and modifications are embraced by the appendedclaims, they constitute part of the present invention.

We claim:

1. A detergent-iodine composition providing enhanced iodine color inhigh use dilution, said composition consisting essentially of adetergent-iodine complex providing a germicidally effective amount ofiodine, the detergent component of said complex being a water solubleprimary alcohol-ethylene oxide condensate having an alcoto Zn-l mols ofethylene oxide, where n is the average number of carbon atoms in saidalcohol moiety, the ratio of detergent to available iodine in saidcomplex being at least 5:1.

2. A detergent'iodine composition as defined in claim 1 wherein saidalcohol moiety has an average number of carbon atoms within the C to Crange.

3. A detergent-iodine composition as defined in claim 1 wherein saiddetergent is a liquid condensate of a C to C primary alcohol with atleast 7.5 moles of ethylene oxide.

4. A detergent-iodine composition as defined in claim 1 wherein saiddetergent is a liquid condensate of a primary alcohol having an averagecarbon content of C with about 7.6 moles of ethylene oxide.

5. A detergent-iodine composition as defined in claim 1 wherein saiddetergent is a liquid condensate of a C primary alcohol With about 8.1moles of ethylene oxide.

6. A detergent-iodine composition as defined in claim 1 wherein saiddetergent is a solid condensate of a pri mary alcohol having an averagecarbon content within the C to C range with about 10 to 20 moles ofethylene oxide.

7. A detergent-iodine composition as defined in claim 1 wherein saiddetergent is a solid condensate of a C primary alcohol with about 20moles of ethylene oxide.

8. A detergent-iodine composition as defined in claim 1 wherein thedetergent:iodine ratio is within the range of 5:1 to 20:1.

9. A detergent-iodine composition providing enhanced iodine color inhigh use dilution, said composition consisting essentially of adetergent-iodine complex providing a germicidally elfective amount ofiodine, the detergent component of said complex being a water solublealkylphenol-ethylene oxide condensate in which the alkyl substituentcomprises one or more primary aliphatic radicals having a total of 12 to18 carbon atoms, and the number of mols of ethylene oxide is within therange of 0.8 to 3.0 times the number of carbon atoms in said alkylsubstituent, the ratio of detergent to available iodine in said complexbeing at least 5:1.

10. A detergent-iodine composition as defined in claim 9 wherein saiddetergent is a condensate of dodecylphenol with 12 moles of ethyleneoxide.

11. A detergent-iodine composition as defined in claim 9 wherein thedetergentziodine ratio is within the range of 5:1 to 20:1.

12. A detergent-iodine composition providing enhanced iodine color inhigh use dilution, said composition consisting essentially of adetergent-iodine complex providing a germicidally effective amount ofiodine, the detergent wherein R is C to C primary alkyl, EO and POrepresent ethylene oxide and propylene oxide respectively, the Weightpercent of E is Within the range of 0 to 45% in one of the blocks x, yand within the range of 60 to 100% in the other of the blocks x, y, andthe total number of moles of combined EO and PO is in the range of 6 to40 moles, with 1 to 10 moles in the PO rich block, and 5 to moles in theE0 rich block, the ratio of detergent to available iodine in saidcomplex being at least 5: 1.

13. A detergent-iodine composition as defined in claim 12 wherein theblock x contains 0 to E0 and provides 1 to 4 moles of alkoxide, and theblock 3 contains to 90% E0 and provides 5 to. 20 moles of alkoxide.

14. A detergent-iodine composition as defined in claim 12 wherein theblock x contains 25% E0 and provides 4.3 moles of alkoxide", the block ycontains E0 and provides 14.6 moles of alkoxide, and R is C allgyl.

15. A detergent-iodine composition as defined-in claim 12 wherein thedetergentziodine ratio is within the range of 5:1 to 20:1.

References Cited UNITED STATES PATENTS 2,868,686 1/1959 Shelanski et al.16717 2,931,777 4/ 1960 Shelanski 252-406 3,028,299 4/1962 Winicov etal. 16717 3,029,183 4/ 1962 Winicov et a1 252-106 X FOREIGN PATENTS540,358 4/ 1957 Canada.

LEON D. ROSDOL, Primary Examiner. ALBERT T. MEYERS, Examiner. S. E.DARDEN, Assistant Examiner.

1. A DETERGENT-IODINE COMPOSITION PROVIDING ENHANCED IODINE COLOR INHIGH USE DILUTION, SAID COMPOSITION CONSISTING ESSENTIALLY OF ADETERGENT-IODINE COMPLEX PROVIDING A GERMICIDALLY EFFECTIVE AMOUNT OFOIDINE, THE DETERGENT COMPONENT OF SAID COMPLEX BEING A WATER SOLUBLEPRIMARY ALCOHOL-ETHYLENE OXIDE CONDENSATE HAVING AN ALCOHOL MOIETY WITHAN AVERAGE CARBON CONTENT WITHIN THE RANGE OF C12 TO C18, AND N/2-1 TO2N-1 MOLS OF ETHYLENE OXIDE, WHERE N IS THE AVERAGE NUMBER OF CARBONATOMS IN SAID ALCOHOLMOIETY, THE RATIO OF DETERGENT TO AVAILABLE IODINEIN SAID COMPLEX BEING AT LEAST 5:1.
 9. A DETERGENT-IODINE COMPOSITIONPROVIDING ENHANCED IODINE COLOR IN HIGH USE DILUTION, SAID COMPOSITIONCONSISTING ESSENTIALLY OF A DETERGENT-IODINE COMPLEX PROVIDING AGERMICIDALLY EFFECTIVE AMOUNT OF OIDINE, THE DETERGENT COMPONENT OF SAIDCOMPLEX BEING A WATER SOLUBLE ALKYLPHENOL-THYLENE OXIDE CONDENSATE INWHICH THE ALKYL SUBSTITUENT COMPRISES ONE OR MORE PRIMARY ALIPHATICRADICALS HAVING A TOTAL OF 12 TO 18 CARBON ATOMS,AND THE NUMBER OF MOLSOF ETHYLENE OXIDE IS WITHIN THE RANGE OF 0.8 TO 3.0 TIMES THE NUMBER OFCARBON ATOMS IN SAID ALKYL SUBSTITUENT, THE RATIO OF DETERGENT TOAVAILABLE IODINE IN SAID COMPLEX BEING AT LEAST 5:1.
 12. ADETERGENT-IODINE COMPOSITION PROVIDING ENHANCED IODINE COLOR INHIGH USEDILUTION, SAID COMPOSITION CONSISTING ESSENTIALLY OF A DETERGENT-IODINECOMPLEX PROVIDING A GERMICIDALLY EFFECTIVE AMOUNT OF IODINNE, THEDETERGENT COMPONENT OF SAID COMPLEX BEING A WATER SOLUBLE PRIMARYALCOHOL-ALKYLENE OXIDE CONDENSATE REPRESENTED BY THE FORMULA